Future of BIOS RAID support in the installer - devel - Fedora mailing-lists

23 Nov 2022


      Hi, I am planning to change how we support BIOS RAID (sometimes also
called Firmware or Fake RAID) in the installer in the future. I plan
to go through the official Fedora change process for Fedora 38, but
I'd like to get some feedback first.
We are currently using dmraid to support these types of RAIDs in
blivet[1] (storage library the Anaconda installer uses) and we would
like to replace it with mdadm. The main reason is that dmraid is no
longer actively maintained, but it will also mean one less dependency
for the installer (we use mdadm for the software RAID support) and one
less service running during boot (dmraid-activation.service).
The potential issue here is that mdadm doesn't support all BIOS RAID
types. mdadm supports only Common RAID Disk Data Format standard[2]
(DDF) and Intel Matrix Storage Technology (IMSM) so by switching to
mdadm we would remove support for some of the older formats that
existed before DDF was standardized. I am not sure how many people are
still using these older RAIDs and the main reason for sending this
email is to find out. So if you are using a BIOS RAID on your system,
can you check what kind? You can find out simply by checking the
filesystem type on the underlying disk(s) reported by for example
`lsblk -f`. Types supported by mdadm are "ddf_raid_member" and
"isw_raid_member". Types supported only by dmraid are
"adaptec_raid_member", "hpt***_raid_member", "jmicron_raid_member",
"lsi_mega_raid_member", "nvidia_raid_member",
"silicon_medley_raid_member" and "via_raid_member". So if you have one
of the latter ones and you'd be impacted by this change, please let me
know so we can reconsider this change. Note that this would affect
only the installation process, I know some external and NAS drives use
BIOS RAID and these won't be affected, dmraid is not being removed
from the repositories (at least I am not aware of this right now, some
distributions are already planning to remove dmraid completely).
[1] https://github.com/storaged-project/blivet
[2] https://www.snia.org/tech_activities/standards/curr_standards/ddf
Regards
Vojtech Trefny
vtrefny@redhat.com